Ionization detector



Across America, people are sleeping safely tonight because they are using a household smoke detector that will sound an alarm in the event of a fire. Whether it is a smoldering fire that causes a photo-ionization detector to sound a buzzer, or a hot fire that is more easily detectable using the standard ionization detector, the alarm will sound and cause people to wake from deep sleep. Sensing the emergency, the occupants will escape from the house and call the fire department. Members of the department will arrive and check the home for pets and missing people, then put out the fire so that smoke damage and destruction by flames is minimized. Insurance rates will stay low because agents know that the loss of property and life will be less when there is a smoke detector installed. Sleeping occupants will not be burned, and hospitalization or other medical treatment for smoke inhalation will not be required.



Invented in Nazi Germany n the 1930s, ionization detectors were developed for the protection of bomb and explosives factories. Munitions and other ordinances were dangerous to work with, and workers needed to be warned of fires that could potentially cause the munitions to explode. Operating on household electricity or 9-volt batteries, smoke detectors today safeguard people while they are sleeping and unaware of the hazards of smoke that a nearby fire could be producing right in their own home.

The National Fire Protection Association (NFPA) recommends that all homes have smoke detectors installed to prevent loss of life. Local fire codes require smoke detectors in new homes and in apartments. Fire alarm detectors safe lives when they detect small amounts of smoke with sensitive sensors. Audio, visual or tactile alerts are emitted to warn occupants who are sleeping in the bedroom of danger. Suffocating gasses and extreme heat are avoided when they escape to safety. But these sensors and the fire protection that they provide are available all because of because a manmade element called Americium-241.

In a smoke detector, Americium-241 is contained in a special chamber open to environmental air. Smoke, in the form of particulate matter floating in the air is detected in the special chamber. Americium-241 has a half-life of 432 years, so operation of the device will be stable for the lifetime of the device. The detector works by the unstable element emitting low levels of radiation in the form of alpha particles. The radioactive element doesn't emit beta waves, but does release small amounts of gamma radiation. Alpha radiation, on the order of micro curies and with low penetrative power, causes ionization of the air molecules when an alpha particle strikes an atom. This kinetic energy is absorbed by the atom and raises the energy of an electron.